BOC Aviation will lease the aircraft to Jakarta-based Lion Air Group, with deliveries scheduled for 2019 and 2020. Lion Air has the option to buy four of the aircraft on delivery.

The fresh order comes after the largest customer for the Airbus A330neo, AirAsia X (AIRX.KL), last month expanded an order by 34 jets to 100, helping to ease doubts over the model’s relatively slow sales.

It was not clear whether the order had been logged already in the Airbus order book without the customer being identified.